Leaky mode systems may be used for holographic video, e.g., flatscreen, scanned aperture, and near-eye holographic video systems. In a leaky mode system, which generally comprises multiple leaky mode devices, surface acoustic waves (“SAW”) for a leaky mode device may be generated by a “delay line” (or “channel”) configuration that encodes and decodes electrical information to and from an acoustic wave so that the input information is the same as the output information. The encoding may happen at a transducer at the beginning of the delay line, and the decoding may happen at a transducer at the end of the delay line. Although the information is the same on the input signal and output signal the signal is, in general, attenuated when it arrives at the decoding transducer at the end of the delay line.
In leaky mode systems, it is often complex to drive large leaky mode arrays. Unlike non-leaky-mode systems, in which pixels persist once they are written, in a leaky-mode system pixels do not persist, but “run away” as SAWs traveling at thousands of meters per second across the substrate that is the medium for SAW wave propagation. In a leaky mode system, an image does not persist unless it is constantly rewritten.
For example, small aperture leaky mode devices must be updated frequently—e.g., every few microseconds. This frequent updating is complex and consumes resources, e.g., computing, electronics, and power resources. The resource consumption resulting from frequent updating is magnified in large leaky mode systems. Although “large” is not an exact term, a system with more than 18 channels may be considered “large.” In general, each channel requires a VGA cable's worth of information (e.g., 400 million pixels per second per color channel). A single computer with three dual-head graphics cards might have up to 18 usable channels in a leaky mode system. In general, using more than 18 channels results in significant complexity and resource consumption for updating small aperture leaky mode devices that are part of an array of such devices.
What is needed are improvements to reduce the complexity of driving large leaky mode arrays.